This patent application contains a microfiche appendix which contains a program listing for the computer program used in the practice of this invention, and a set of (40) microfiche cards.
The present invention relates generally to medical devices utilized to treat intensive care patients and more particularly to a self-contained transportable life support system which is utilized in the resuscitation, stabilization, and transport of medical patients such as heart attack victims, stroke victims, accident victims and battlefield casualties.
The need to transport medical patients and persons suffering from various medical emergency conditions such as heart attacks, strokes, etc. is well-known. Medical personnel speak of a xe2x80x9cgolden hourxe2x80x9d within which such a medical patient must be transported to a medical facility so that proper medical care can be provided therefor. The survival rate for such medical patients is greatly enhanced if they are transported to the medical facility within the golden hour.
However, as those skilled in the art will appreciate, it is often difficult to transport a patient to a remotely located medical facility in a timely manner, particularly within the golden hour. Frequently accidents occur at remote locations and thus require a substantial amount of time to transport the medical patient to a distant hospital. Also, in battlefield situations, it is frequently impossible to transport a casualty immediately. In either instance, a hospital may be located hundreds, if not thousands, of miles from a hospital, thus necessitating several hours of transport time. As such, it is frequently beneficial to perform various emergency medical procedures at the site of the medical problem, and then to attempt to provide ongoing medical care during transport. By providing such early emergency medical care and by continuing medical treatment during transport to a remote hospital, the mortality rate of such transported medical patients is substantially reduced.
It is well-known to use various different medical devices in the field, i.e., at locations remote from a medical facility, so as to enhance a medical patient""s chance of survival. For example, it is well-known to use an ECG and a defibrillator upon heart attack victims, so as to monitor the condition thereof and so as to provide medical treatment therefor in the field.
Typically, the medical patient is placed upon a stretcher and then various different medical devices are used thereupon, as necessary. During transport the medical devices may either be temporarily disconnected from the patient or, alternatively, may be hand carried along therewith by additional personnel. However, disconnection of the medical devices from the patient results in the undesirable disruption of medical monitoring or treatment therefor. Hand carrying the medical devices along with the patient requires extra personnel, which may not be available, or for which there may not be adequate room within the transport vehicle.
As such, it is desirable to provide a system for transporting a medical patient wherein the medical devices are carried along with the stretcher. In an attempt to provide such a system for transporting a medical patient while facilitating the continuous use of medical devices thereupon, the Mobile Intensive Care Rescue Facility (MIRF) was developed by the Royal Australian Army Medical Corp. The MIRF is intended to provide sufficient medical equipment to have the capabilities of an intensive care hospital ward. The MIRF is designed so as to facilitate the removal and replacement of the various pieces of medical equipment therefrom for maintenance. The MIRF is specifically designed to accommodate two major roles: the transfer of critically ill people from one point to another, such as from a ward to an x-ray room or from one hospital to another; and the bringing of life support systems quickly to the scene of an accident or other medical emergency.
The MIRF can be configured to include a blood pressure cuff, an invasive blood pressure monitor, a body temperature sensor, a heart rate sensor (finger clip sensor), an oxygen saturation sensor, an exhaled air carbon dioxide sensor, and an electrocardiograph, so as to facilitate medical monitoring of a patient. Further, the MIRF can include a ventilation system, a volumetric infusion pump, a syringe pump, a suction unit, and a defibrillator so at to facilitate medical treatment.
However, since the various medical devices of the MIRF are not integrated with the housing thereof, the inclusion of all of the medical devices results in a system having substantial weight. Further, since the various medical devices of the MIRF are not integrated with the housing thereof, the volume occupied thereby and the electrical power consumption of the medical devices thereof are not optimal.
As such, it would be desirable to provide an integrated system which utilizes a single power supply and which eliminates redundant components, so as to achieve a substantial reduction in weight, volume, and power consumption.
Another contemporary system is the MOBI described in U.S. Pat. No. 4,957,121, issued to Icenogle et al. on Sep. 18, 1990. The MOBI is similar to the MIRF in concept. That is, like the MIRF, the MOBI utilizes off-the-shelf medical devices which are contained attached to housing thereof, so as to be transportable therewith, thus eliminating disruptions in the medical care provided thereby during transport.
However, also like the MIRF, the MOBI is not an integrated system and thus possesses substantially greater weight, volume, and power consumption than desirable.
Further examples of such contemporary life support systems include those disclosed in U.S. Pat. Nos. 4,584,989; 4,352,991; 4,691,397; 3,304,116; and 3,341,246.
U.S. Pat. No. 4,584,989 discloses a life support stretcher bed adapted to accommodate patients in intensive or cardiac care units in hospitals. The life support stretcher bed is broadly adapted for electrical medical devices, medical supplies and features an under carriage including a support structural, wheels, a patient housing with a mattress, an electrical power source and supports for mounting the medical equipment.
U.S. Pat. No. 4,352,991 teaches a life support system adapted for field use in a vehicle with available power and includes electrically operable life support units, means for supporting the life support units, a patient stretcher, and a dc power source adapted for battery or remote power source.
U.S. Pat. No. 4,691,397 teaches a device for carrying the life supporting devices of a bedridden patient including a table like means for supporting the devices, an IV holder, wheeled transport means and a hospital bed footboard securing means.
U.S. Pat. No. 3,304,116 teaches a multiple purpose wheeled carriage capable of supporting a stretcher carrying a patient, adapted with four castered wheels, a fifth wheel, a rectangular frame, a fluid pressure actuated means for vertical adjustment, operating and control means and patient support means.
U.S. Pat. No. 3,341,246 teaches a hospital stretcher adapted broadly with a litter structure having telescopic post elements and other means for manipulating the patient to various positions.
It is frequently desirable to isolate a medical patient from the environment during transport thereof to a medical facility. It is also frequently desirable to isolate the medical patient from care givers and other personnel. Isolating the medical patient from care givers and other personnel may be desirable when the medical patient has a suppressed immune system, open wound, or when the presence of a contagion is suspected among the care givers and/or other personnel. It is desirable to isolate the patient from the environment when the environment contains substances which may be detrimental to the medical patient. For example, if the patient has suffered severe blood loss or is experiencing difficulty breathing, then it is desirable to prevent the patient from breathing dust, engine exhaust, smoke, etc. It is also desirable to isolate the medical patient from the environment when bacteriological, chemical and/or radiological hazards are present, as may occur during battlefield conditions.
It may be desirable to isolate the care givers from the medical patient in instances where the medical patient is suspected of having a contagious disease, or has been exposed to bacteriological, chemical or radiological contamination. As such, it is desirable to provide a means for isolating the patient from the environment and care givers, as well as isolating the care givers from the patient.
As discussed above, increased transit times make the initial preparation of the medical patient substantially more crucial. This may include resuscitation, and in any event must be sufficient to avoid causing further injury to the medical patient during transport. It is generally also necessary to provide continuous care, i.e., stabilization, for the patient during transit.
Proper care during transit frequently includes ventilation, suction, fluid infusion and possibly defibrillation. Further, it is highly desirable to monitor blood pressure, temperature and respiration. It may also be desirable to monitor ventilation gases for pO2 and pCO2, and also to monitor O2 saturation, cardiac output and local blood flow. By providing such care and monitoring, the probability of survival for the medical patient is greatly enhanced. Variations in the monitored parameters may signal the need for an immediate change in the medical care being provided.
Further, such longer transit times make environmental protection for the medical patient even more desirable. For example, increased transit time makes loss of body heat a much greater concern. Thus, protection from cold and rain is desirable.
Although, as discussed above, various different mobile intensive care systems have been proposed, such contemporary mobile intensive care systems are not suitable for transport via military vehicles having standard NATO stretcher holders. Such military vehicles require that the stretcher or other housing upon which the medical patient rests, along with the medical patient, fit within a well defined and rigid envelope so as not to interfere with adjacent vehicle structures and/or other patients and stretchers. No contemporary mobile intensive care system is known which fits with this envelope. Thus, such prior art mobile intensive care systems cannot be efficiently carried via such military vehicles. This means that fewer such battlefield casualties can be transported via a particular military vehicle when such contemporary mobile intensive care systems are utilized, thus inherently causing undesirable delays in transport and also undesirably increasing the risk of mortality.
The UH-60 Blackhawk helicopter, the UH-1 Huey helicopter, the HumVee ambulance, the C-130 Fixed Wing aircraft, and the C-141 Fixed Wing aircraft all utilize standard NATO stretcher holders such that a plurality of such NATO stretchers, having battlefield casualties laying thereupon, can be efficiently carried thereby. For example, in the UH-60 Blackhawk helicopter, such stretchers are mounted to a vertical bulkhead carousel in a stacked configuration, such that the number of battlefield casualties so carried is maximized.
In order to facilitate evacuation of a medical patient from the battlefield to a remote hospital, a number of such military vehicles are commonly used. For example, a HumVee may be utilized to transport the medical patient to a helipad where the medical patient is then transported via a UH-60 Blackhawk or UH-1 Huey helicopter to an airfield. From the airfield the medical patient is then transported, typically, via C-130 or C-141 fixed wing aircraft to an airport near the remote hospital. As mentioned above, all of these military vehicles presently have stretcher holders which are specifically configured to hold the NATO standard stretcher.
In order to be carried via such military vehicles, a life support system must fit within the standard stretcher holders of such vehicles and still leave enough room for the medical patient resting thereon. Of course, the support system must not interfere with adjacent, e.g., stacked, medical patients and/or life support systems. However, to date, no such life support systems are known which are specifically configured to be compatible with such standard stretcher holders.
Since contemporary mobile intensive care systems are not configured for transport via military vehicles utilizing standard NATO stretcher mounts, it is frequently necessary to remove the medical patient therefrom, so as to facilitate such transport. Such removal of the medical patient from a contemporary mobile intensive care system may require disconnection from or disruption of desirable medical treatment, thus increasing the risk of mortality. Further, as those skilled in the art will appreciate, removing a medical patient from a mobile intensive care system, such that the medical patient can be placed upon a stretcher for transport aboard a military vehicle utilizing standard NATO stretcher mounts, tends to exacerbate existing injuries and thus tends to further increase the rate of mortality for such battlefield casualties.
As such, it is desirable to provide a single mobile intensive care system upon which the medical patient is placed at the battlefield and upon which the medical patient remains throughout the entire trip to the remote hospital.
Further, such contemporary mobile intensive care systems require skilled operators having extensive training to assure that proper care is provided to the medical patient. Although mobile intensive care systems requiring such extensive training are generally suitable for use in civilian applications, it is highly desirable to minimize the amount of skill and training required for use in battlefield situations. This allows medics or medical care givers to be trained in a minimum amount of time. It also facilitates use of the life support system when trained personnel are not available (as is often the case in battlefield situations). Thus, it is desirable to provide a mobile intensive care system which requires minimal skill and training for such battlefield applications.
Further, since the individual medical devices of contemporary mobile intensive care systems are not integrated with one another, the medical care provided thereby is not optimized. This lack of integration further enhances the requirement for trained personnel. Additionally, such lack of integration necessitates constant monitoring of the medical patient during transport. Constant monitoring of the medical patient is often either difficult or impossible, since skilled medical personnel are generally either not available or are highly taxed during such evacuation procedures.
As such, it is desirable to provide means for preparing a medical patient for a lengthy transport, i.e., stabilizing the medical patient, and for providing the necessary medical care during such transport. It is also desirable to provide medical devices which are integrated so as to mitigate the skill and training required for the proper operation thereof, and so as to facilitate automated operation thereof such that minimal attention of a care giver is required during transport. It is also desirable to provide a mobile intensive care system wherein the medical devices thereof cooperate with one another so as to optimize medical care provided thereby. Further, it is desirable to provide a mobile intensive care system which protects the medical patient from the environment, so as to mitigate the detrimental effects thereof.
The present invention specifically addresses and alleviates the above-mentioned deficiencies associated with the prior art. More particularly, the present invention comprises a self-contained transportable life support system for resuscitation, stabilization, and transport of a patient. As used herein, the terms medical patient and patient are defined to include patients and/or victims of any accident and/or medical condition resulting in the need for emergency medical care. Thus, the term medical patient includes victims of heart attacks and strokes, as well as victims of accidents and wartime casualties. The system comprises an environmentally controlled housing for receiving and supporting a patient, and a plurality of medical devices disposed within the housing. A control circuit is attached to the housing such that at least a portion of the control circuit extends to an external surface of the housing. The control circuit regulates operation of the medical devices and environmental conditions within the housing in response to monitored life support conditions of the patient.
The control circuit is programmably controllable to regulate operation of the medical devices and life support conditions of the patient independent of operator intervention. The control circuit preferably comprises a closed-loop control system.
The medical devices preferably comprise a ventilator, suction device, fluid infuser, defibrillator, oxygen enricher/generator, electrocardiograph, electroencephalograph blood pressure monitor, temperature sensor, respiration volume and rate monitor, ventilator gas monitor, O2 saturation monitor, and a cardiac rate and cardiac output and local blood flow monitor, and a device for performing blood chemistry analysis.
A heater is preferably disposed within the housing and in electrical communication with the control circuit, for heating an interior portion of the housing so as to maintain the interior portion above a predetermined minimum temperature.
Similarly, a cooler is preferably disposed within the housing and in electrical communication with the control circuit, for cooling an interior portion of the housing so as to maintain the interior portion below a predetermined maximum temperature.
An air filtration system is preferably disposed within the housing and in electrical communication with the control circuit, for filtering air within the housing.
The medical devices comprise at least one medical monitoring device for monitoring at least one life support condition of the patient and at least one medical treatment device for providing medical treatment to the patient. The medical devices providing treatment are regulatable by the control circuit in response to signals from the medical monitoring devices.
A communication circuit attached to the housing provides communications between the control circuit and a remote location. The communication circuit preferably comprises a transmitter for transmitting information representative of patient life support conditions and patient physiological status and a receiver for receiving externally generated remote control signals. The control circuit is responsive to the remote control signals, such that patient life support conditions are regulatable in response to the remote control signals. The control circuit preferably comprises a general purpose microprocessor.
The housing has an interior portion which is configured to receive and engage a stretcher. An exterior portion is configured to engage vehicular mounted stretcher supports.
The housing preferably comprises four stretcher retention members disposed within the housing for receiving and engaging a stretcher within the housing. Each of the stretcher retention members comprises a stretcher engagement mechanism operative to provide locking engagement to the stretcher solely in response to placement of the stretcher upon the stretcher engagement mechanism.
The control circuit preferably comprises first and second battery sections. A charging circuit selectively charges either one of the first and second battery sections or both sections simultaneously. The control circuit is operative to alternately charge the first battery section from an external power source while maintaining the second battery section ready to power the medical devices during an interruption of external power. Then the charging control circuit is operative to charge the second battery section from the external power source while maintaining the first battery section ready to power the medical devices during an interruption of external power. Thus, while each battery section is being charged, the other battery section is in a stand-by mode, such that it serves as a backup power source and takes over operation of the medical devices in the event that the external power source which is providing electrical power to the medical devices fails.
The medical devices preferably comprises a temperature monitoring system connectable to a patient for monitoring a body temperature of the patient and a temperature control system connectable to the patient for controlling the body temperature of the patient. The temperature control system alternatively comprises an extracorporeal blood temperature controller for regulating the blood temperature of the patient in response to the temperature monitoring system. Alternatively, the temperature control system comprises a temperature controlled water jacket.
The temperature monitoring system preferably comprises either an indwelling rectal temperature probe, an infrared eardrum temperature sensor, an axillary temperature sensor, or an intraesophageal temperature sensor.
Two invasive pressure sensors are preferably provided, so as to facilitate simultaneos measurement of blood pressure and intracranial pressure, for example.
According to one preferred configuration of the present invention, the temperature control system directs temperature controlled air about the patient in response to the temperature monitoring system, so as to maintain the temperature of the patient within a desired range.
The housing is preferably sealable so as to isolate the patient therein from chemical, biological and radiological conditions existing external to the housing. A pressure regulating mechanism disposed within the housing and in electrical communication within the control circuit regulates pressure within the housing so as to facilitate such isolation.
The control circuit preferably comprises an audio/visual device disposed external to the housing and in electrical communication with the control circuit, for displaying patient life support conditions. The audio/visual device preferably displays treatment instructions in response to patient life support conditions.
The control circuit preferably comprises a power regulator for regulating application of electrical power to the medical devices in accordance with an assigned priority status of the medical devices. The controller is preferably operative to modify the assigned priority status of medical devices in response to the patient support conditions in order to preserve the limited battery resource.
The control circuit is preferably operative to simulate a plurality of life support conditions, to monitor an operator""s utilization of the medical devices in response to the simulated life support conditions, and to evaluate the effectiveness of the operator""s utilization of the medical devices.
The housing preferably comprises a hyperbaric chamber and a hypobaric chamber, preferably formed of a lightweight, durable polymer or composite material.
The control circuit preferably comprises. a medical data reader for receiving medical data from a medical data storage device. The control circuit is operative to regulate operation of the medical devices in response to the received medical data. The medical devices preferably comprise a xe2x80x9cdog tagxe2x80x9d having medical data stored therein, an identification card having medical data stored therein, or a data storage device implanted beneath a patient""s skin.
These, as well as other advantages of the present invention will be more apparent from the following description and drawings. It is understood that changes in the specific structure shown and described may be made within the scope of the claims without departing from the spirit of the invention.